Hi @3SIX5_Digital Steve,
We tried to do what you described. But we probably missed something here… 
Sorry to come back to you on this!
The initial state for the original pink underline got a size 0. We set the size of the pink line to ‘auto’, so the line extends from left to right when mouse hovers over the nav item.
Since we added a bottom pink border to the current nav item, we ended up having a thicker pink border when hover in and out over the current nav item because of the original pink underline.
We don’t suppose there’s a way to only turn off the the underline animation for the current tab underline when hovering over the current tab? That would then avoid have 2 pink underlines.
We created a new read-only link here
Thank you 